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Argument for why can't I see through a table

  1. Oct 15, 2009 #1
    1. The problem statement, all variables and given/known data
    Objects are composed of atoms. Atoms are nucleii surrounded by electrons. The electrons are tiny in comparison to the gaps between each other, and between electrons and the nucleus. This means that there are significant gaps between atoms in objects.

    2. Relevant equations
    A typical human eye will respond to wavelengths from about 380 to 750 nm.
    The size of an electron is 2.82 × 10-15 m.
    The diameter of an atom ranges from about 0.1 to 0.5 nanometers

    3. The attempt at a solution
     
  2. jcsd
  3. Oct 15, 2009 #2
    What is happening to the energy of the photons of light?
     
    Last edited: Oct 15, 2009
  4. Oct 15, 2009 #3

    mgb_phys

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    Also your first arguement would apply equally well to glass.
    In fact carbon atoms are closer together in a diamond than they are in coal
     
  5. Oct 18, 2009 #4
    Re: Argument for why I can't see through a table

    Humans can't see the gaps in tables just because they are too small to detect with the human eye. Instruments may be able to detect light from the other side of the table if photons could get through.

    Spacing between carbon atoms is 0.1415 nm
    Atomic diameter is 10^-9 m, or 1nm for helium, and 10-15nm for its nucleus.

    From a model I have seen, the spacing between carbon atoms in diamond is the diameter of one carbon atom. That means that in diamond, there is a similar spacing between the outer electrons in the atom, and the edge of the nucleus, to electrons in the outer orbit of adjacent atoms. It's still easier for photons to pass between atoms than through them though, obviously. I presume that since the atoms are vibrating, and there are so many of them in a solid object, it is impossible for a photon to pass all the way through without colliding with enough atoms to reduce its energy to the point where it gets absorbed.
     
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